Getting started with arduino Part IV

You now this click clack noises for exmple from your car if you want to turn right or left, yes right I mean relay. This will be the stuff that describe in this post, controlling circuits with a relay.

You can find the coil by the mark on the side of your relay case or by line on the top of your relay. Another way: you try to measure the electrical resistance with a multimeter – Ω position, only the coil can be measured by the digital multimeter.